Distribution of Blood Flow Velocity in the Normal Aorta: Effect of Age and Gender

作者:Garcia Julio*; van der Palen Roel L F; Bollache Emilie; Jarvis Kelly; Rose Michael J; Barker Alex J; Collins Jeremy D; Carr James C; Robinson Joshua; Rig**y Cynthia K; Markl Michael
来源:Journal of Magnetic Resonance Imaging, 2018, 47(2): 487-498.
DOI:10.1002/jmri.25773

摘要

Purpose: To apply flow distribution analysis in the entire aorta across a wide age range from pediatric to adult subjects.
Material and Methods: In all, 98 healthy subjects (age 9-78 years, 41 women) underwent 4D flow MRI at 1.5T and 3T for the assessment of 3D blood flow in the thoracic aorta. Subjects were categorized into age groups: group 1 (n = 9, 5 women): 9-15 years; group 2 (n = 13, 8 women): 16-20 years; group 3 (n = 27, 14 women): 21-39 years; group 4 (n = 40, 11 women): 40-59 years; group 5 (n = 9, 3 women): >60 years. Data analysis included the 3D segmentation of the aorta, aortic valve peak velocity, mid-ascending aortic diameter, and calculation of flow velocity distribution descriptors (mean, median, standard deviation, incidence of velocities >1 m/s, skewness, and kurtosis of aortic velocity magnitude). Ascending aortic diameter was normalized by body surface area.
Results: Age was significantly associated with normalized aortic diameter (R = 0.73, P < 0.001), skewness (R = 0.76, P < 0.001), and kurtosis (R = 0.74, P < 0.001), all adjusted by heart rate. Aortic peak velocity and velocity distribution descriptors, adjusted by heart rate, were significantly different between age groups (P < 0.001, analysis of covariance). Skewness and kurtosis significantly increased (P < 0.001) during adulthood (>40 years) as compared with childhood (<21 years). Men and women revealed significant differences (P <= 0.05) for peak velocity, incidence, mean, median, standard deviation, and skewness, all adjusted by heart rate.
Conclusion: Aortic hemodynamics significantly change with age and gender, indicating the importance of age- and gender-matched control cohorts for the assessment of the impact of cardiovascular disease on aortic blood flow.